The risk of heart disease after receiving an antiviral vaccine based on messenger RNA technology is low, but it has not been completely ruled out, and some scientists lament the lack of conclusive studies.
“We have been applying the mRNA vaccine extensively for more than a year and a half and are still not entirely sure” of its cardiovascular risks, American scientists Jing Lu and Walid Galad said in an editorial published in the British Medical Journal. In mid-July.
This opinion article is based on a study published by the same journal on recurring myocarditis and pericarditis, two types of heart inflammation, in patients who received doses of either Moderna or Pfizer/BioNTech vaccine.
The risks were revealed soon after the 2021 vaccination campaigns. Critics of these campaigns used this argument to oppose vaccination.
However, the frequency of these heart problems is rare and does not appear to have led to serious complications in most cases. In addition, COVID-19 itself causes cardiovascular risks.
The editors of the British Medical Journal acknowledge, however, that there are reasons for the scientific community’s dissatisfaction with the degree of knowledge of these risks. Experts agree that “myocarditis is rare after vaccination.” “But to what extent? This issue is of fundamental importance,” they completed.
The study accompanying the article was based on the results of approximately 50 previous fieldwork.
The risk of developing myocarditis among young people is undeniable. And apparently, even if the conclusions are less clear, this risk has more to do with Moderna’s vaccine than with Pfizer/BioN Tech.
Countries such as France have decided to designate the Moderna vaccine for those over the age of 30, while others, such as the United States, have not made this distinction.
What happens to booster doses?
The study did not clarify all the doubts, because the methodologies of work vary widely by each analysis. In addition, some of the data obtained are unsatisfactory. An example is the vaccination of children, which is authorized in many countries, but which is not strictly adhered to, due to parental reluctance.
Although myocarditis appears to be “extremely rare among children aged 5 to 11,” the data is incomplete, the article’s authors explain.
In most cases, myocarditis and pericarditis resolved without risk, but there was no long-term follow-up. Therefore, researchers are unaware of the risks of consequences.
It is also not known if the risk increases again after each booster dose. These data are crucial for planning long-term vaccination campaigns in more developed countries, where basic vaccination is practically completed.
On Friday, a French team published a report, which has not yet been subject to independent verification, with data from the country’s public immunization campaign.
The authors concluded that the risk of developing myocarditis effectively increases with a booster dose of Pfizer/BioNTech and Moderna immunizer, but to a lesser extent with the initial vaccine.
“Moreover, the risks decrease with increasing time between doses,” conclude the study authors, led by epidemiologist Mahmoud Zureik of the French public health agency Epi-Phare.
